First certified Passivhaus homes in Lake District help combat affordable housing shortage
Witherslack is a small community situated on the boundaries of the Lake District National Park. The village has a strong sense of community and has successfully sought creative solutions to the issues facing rural Britain.
The local post office has closed, but a community shop has opened with help from the Witherslack Community Land Trust (WCLT). The local pub, once boarded up, has reopened and is now a thriving hub for the village. However, in the parish, house prices remain beyond local affordability.
To address the local rural housing shortage, an innovative scheme has been developed by WCLT in collaboration with PHT member Eco Arc Architects to design and build two affordable certified Passivhaus dwellings for local families.
Project Team:
|
Client: Local Residents via Witherslack Community Land Trust Architect: Andrew Yeats - Eco Arc Passive House Architects Consultants (M&E, Environmental): Alan Clarke Contractor: Whittle Construction Structural Engineer: Richard Renier Consulting Engineers Developer: Self Build / Community Land Trust |
The houses which have been occupied since June 2015 are the first certified Passivhaus dwellings in the Lake District National Park, and have been self-built on land leased from WCLT and donated by a local landowner.
The cost of these houses to the occupiers is to remain at an affordable level. They can only be sold at a percentage of the true value to other qualifying families within the parish, thus ensuring they are truly affordable in perpetuity. Any increase in value will be held by the trust.
The local community wanted to create two houses that challenged the concept of ‘affordable homes’, resulting in the development of the certified Passivhaus dwellings. The WCLT and the designers wanted to ensure that ‘affordable’ should mean well designed, encompassing the lifetime of the building, and not just the build cost.
Materials:
|
Element |
U-value (W/m2k) |
Materials |
|
Wall |
0.106 (masonry) |
Rendered or timber boarded finish on 100mm blockwork, 300mm Dritherm 37 full fill cavity insulation between 100mm blockwork inner and outer leafs |
|
Roof |
0.07 (flat ceiling) |
Slate on bob-tail truss & slate on JJI-rafter roof with ridge beam |
|
Floor |
0.096 |
Screed on 320mm thick Jablite Premium on beam & block suspended floor |
|
Windows |
0.7 (0.61 g-value) |
uPVC |
The super insulated, low energy houses were built using 300mm insulated cavity walls and 400mm insulated roof to give a consistent all over fabric U-value of less than 0.11 W/m2k. The houses include heavy weight thermal mass to reduce the thermal flywheel effect to a minimum. The windows are Low-E argon filled triple glazed resulting in a centre pane U-value of 0.83 W/m2k. Cold bridging was avoided through careful detailing around all reveals.
Efficient Scandinavian space heating wood burning stoves fuelled from local timbers harvested from the local woodland provide any additional heat required beyond solar gain and heat gains from the occupants and house appliances. Conventional central heating boilers run off fossil fuels were not required.
This flagship project for The Witherslack Community Land Trust and The Lake District National Park Authority shows how new housing can meet strict environmental standards in a sensitive rural setting, yet can still be met affordably.
Further information:
Previous PHT news story - First certified Passivhaus in Cumbria, 16th September 2015
